Coalition's rosy view of constituency size

John Denham (Response, 4 August) makes a powerful case for opposition to the coalition's plebiscite on electoral reform, but the issue of the size of constituencies still has to be properly addressed. Like most MPs I hold regular advice surgeries – three a week in my case – and I see an average of 190 people each month. Of these the vast majority are not on the electoral register and would not even be counted when calculating the size of a constituency.

The reason for this is that the two main reasons for coming to see me are immigration and housing. In the case of the former they cannot vote as they have no settled status in the country, and in the case of the latter they cannot be registered if they are homeless. I have heard of MPs who refuse to see people who are not registered to vote but that seems to me to be a pretty shabby way of operating. I will, however, be penalised for my actions, as only those actually on the roll will count towards the new constituency and the very considerable number of people in addition to those mentioned above who are entitled to vote but, for a huge variety of reasons, resist registration will also remain uncounted.

I'm not looking for an urban exemption but for the coalition to look at the issue as it is, and not through the rosy prism of a settled Liberal Democrat/Tory constituency where housing is a problem of second homes, and immigration difficulties relate to the au pair's visa.